Author Information
Prabhu S*, Mishra N**, Savani G***, Tintoiya I****
(* Senior Consultant, ** Head of Department, *** Consultant, **** Resident Medical Officer Department of Obstetrics and Gynecology, Bhabha Atomic Research Centre Hospital, Mumbai, India.)
Abstract
Torsion of gravid uterus is a rare and a ‘once in a lifetime’ diagnosis for a gynecologist. We present an asymptomatic, antenatally undiagnosed case of uterine torsion that was detected at elective lower segment cesarean section (LSCS). It was well managed surgically avoiding the usually expected complications resulting in a good maternal and neonatal outcome.
Introduction
Rarely does a gynecologist get to see a case of uterine torsion, for many it is once in a life time opportunity, for others they never see this condition.[1] Minor degrees of rotation of gravid uterus about its longitudinal axis are physiological.[2] Uterine torsion is considered when pathological rotation occurs on its long axis of more than 45 degrees.[3] Though the phenomenon of gravid uterine torsion is commonly seen in animals, it is rare in humans. We report a case of uterine torsion which remained asymptomatic and was detected only at elective LSCS.
Case Report
A 30 year old G2 P1 L1 with previous LSCS was registered for antenatal care at our institute. On her ANC visit at 37 weeks, patient had no complaints. Her vital parameters were normal. Obstetric examination revealed pendulous abdomen with poor tone, and a Pfannenstiel scar of previous LSCS. Empty Pawlik’s grip suggested transverse lie of the fetus. Fetal heart sounds were regular at 146 beats/minute. Uterus was relaxed and there was no scar tenderness. She had history of LSCS performed 4 years back for non-progress of labor and fetal distress. Her current pregnancy was otherwise uncomplicated. Her ANC investigations were normal and 3 obstetric ultrasonographic scans (USG) performed in each trimester were normal.
The clinical findings of transverse lie were confirmed by USG which showed fetus in transverse lie with cephalic pole in the right hypochondrium (right dorsoinferior position). Liquor was adequate and placenta was anterior. Elective LSCS was planned at 38 weeks in view of previous LSCS with transverse lie. At LSCS, abdomen was opened with Pfannenstiel incision. After opening the parietal peritoneum, tortuous vessels were visible in the center on the lower part of the uterus. There were no adhesions due to previous surgery. Prior to planning uterine incision, routine anatomical delineation of round ligaments was performed, as palpation of round ligaments and centralization of uterus is our routine practice in all LSCS cases. We noticed that the cornual structures of the right side were more towards the left crossing the mid-line. Right ovarian ligament was seen superiorly in the midline, tortuous vessels seen were identified as the right mesosalpingeal vessels and right sided round ligament was seen inferiorly. Considering the right lateral wall of the uterus facing anteriorly, pathological rotation of the uterus and uterine torsion was suspected. (Figure 1). The fetus was in transverse lie with cephalic pole in the right hypochondrium and dorso-inferior position. (Figure 2)
Figure 1. The right sided adnexal structures; ovarian ligament (yellow arrow), fallopian tube (black arrow), round ligament (blue arrow) seen at LSCS.
Figure 2. Diagrammatic representation of fetus in transverse lie (dorso-inferior) with head in right hypochondrium.
Uterine position was corrected manually without difficulty. After correction of uterine torsion the fetal presentation changed from transverse lie to longitudinal lie (floating vertex). Utero-vesical fold of the peritoneum was identified, opened transversely and bladder was retracted with Doyens' retractor. Lower uterine transverse incision was taken. Liquor was clear. A 3.415 kg, male child was delivered by vertex. Baby cried immediately after birth and 1 minute APGAR was 9/10.
Figure 3. Post LSCS view of uterus showing normal cornual structures, anterior lower uterine segment incision with well dissected utero-vesical fold of peritoneum
The placenta which was detected to be located anteriorly on preoperative USG was found to be fundo-posterior during LSCS. After uterine closure, bilateral tubal ligation was performed as the couple had opted for it and abdomen was closed in layers. Post operative period was uneventful. Both mother and baby were discharged on post operative fifth day.
Discussion
Physiological, slight degree of rotation of the pregnant uterus is seen to the right in 80% and towards the left in 20% cases.[3] Uterine torsion is considered when rotation of the uterus occurs on its long axis of more than 45 degrees.[3] Predisposing factors may include uterine anomalies, fibroids, adhesions, abnormal pelvis, placenta previa or malpresentation, especially transverse lie.[3] In 20% cases, no causative factor is apparent.[3]
In our case, though the patient had previous history of cesarean section, there were no adhesions at the time of present LSCS. On evaluating intra operative findings in our case we presume that acute anteversion of the uterus followed by pathological torsion towards left must have occurred as the right sided round ligament was seen inferiorly and ovarian ligament was seen superiorly crossing the midline towards the left side. (Figure 1)
Acute anteversion of the gravid uterus occurs with a pendulous belly. Malpresentations are naturally more common in these cases. The torsion does not occur in case of an anatomically normal uterus.[2]
On evaluating the cause of torsion in our case, we realized pendulous maternal abdomen must have caused acute anteversion of the gravid uterus leading to transverse lie, which further must have contributed as predisposing factor for the torsion. We think transverse lie was consequence and not the cause; and pendulous abdomen was the possible cause of uterine torsion.
Acute torsion compromises the uterine circulation, hence can present as acute abdominal crisis with pain, shock, bleeding as in case of abruptio placentae. Torsion during labor can lead to obstructed labor and its severe complication of uterine rupture.[3]
The overall maternal mortality rate (MMR) associated with the torsion of gravid uterus is about 13 %. It is directly related to the duration of gestation and degree of twisting. Before 5 months it is 0 % while at term it reaches 18.5 %. In 1951, MMR was 7.4% with 90-180 degrees which rose to 50% with 180-360 degrees of torsion. After 1976, there is no reported maternal mortality.
The perinatal mortality also increases with degree of torsion. Between 90-180 degrees it is 20-24 % and may reach as high as 75 % when rotation is more than 180 degrees. Fetal mortality rate reported by Jensen between 1876-1992 was 12 % (212 cases) while between 1996-2006 was 18 % (38 cases).[4]
Our patient was asymptomatic and as the degree of torsion was 90-135 degrees to the left (levorotation), there was no compromise of uterine blood supply. Hence, maternal and neonatal outcomes were unaffected. Antenatal diagnosis by imaging USG is difficult. Nicholson et al have suggested X-shaped configuration of upper vagina on MRI as a sign to diagnose uterine torsion, which is normally visualized as a ‘H’ shaped structure.[5]
An unexpected uterine torsion at term was found during cesarean section by Kremer et al. In their reported case, a changing placental localization on ultrasound from the left to the right side was recorded just before the operation. They suggested this may be a useful sign to diagnose uterine torsion earlier.[1]
As our patient was registered for antenatal care, she had 3 ultrasonographies performed in each trimester. Retrospectively, we analyzed placental localization. It was posterior till mid-trimester (18 weeks) USG, which then was noted anteriorly at and after 28 weeks scan. This finding and its significance was overlooked antenetally, as USG’s were performed by different sonologists. We can now consider this as the time of torsion; after mid-trimester.
Usually uterine torsion is found on laparotomy or at cesarean section. If recognized prior to fetal delivery then manual correction of torsion followed by delivery of fetus is the treatment option.[6] Wilson D et al reviewed the literature of uterine torsion during pregnancy and found posterior hysterotomy is usually performed inadvertently due to non-recognition of torsion or deliberately due to impossible detorsion. The anatomical land marks should be defined prior to uterine incision, to prevent injuries to other organs and blood vessels.
In our present case, inadvertent injury to the blood vessels and hysterotomy at sites other than the anterior lower uterine segment was prevented by routine practice of palpation of bilateral round ligaments making us aware of this condition and allowing the correction of rotation of the uterus prior to the uterine incision.
As the couple opted for permanent method of sterilization the chance of recurrence of torsion in future pregnancy is ruled out.
Conclusion
Gravid uterine torsion is rare in humans. The clinical presentation of the condition is variable from asymptomatic to acute abdomen. Clinical examination and ultrasonography may not be sufficient for establishing the diagnosis antenetally. Most of the time the diagnosis is made at the time of laparotomy. But it is very important to identify the uterine torsion prior to uterine incision for reducing intraoperative complications, maternal and fetal morbidity and mortality. Incorporating routine practice of palpation of bilateral round ligaments and correction of rotation of uterus prior to uterine incision at LSCS can diagnose pathological degrees of uterine rotation and prevent inadvertent injury to the blood vessels, other organs and hysterotomy at sites other than the anterior lower uterine segment respectively. Hence, we strongly recommend this (palpation and correction) technique as routine practice at the time of LSCS.
References
- Kremer JA, van Dongen PW, Torsion of the pregnant uterus with a change in placental localization on ultrasound; a case report. Eur J Obstet Gynecol Reprod Biol. 1989; 31(3):273-5.
- Donald I. Local abnormalities. Donald I. Practical Obstetric Problems.5th ed.New Delhi: B.I.Publications Pvt.Ltd; Reprinted 1998, pp 262-63.
- Pascali D. Uterus and vagina. Posner GD, Jessica DY, Black AY, Jones GD. eds. In Oxorn -Foote. Human Labor and Birth, 6th ed. India; McGraw Hill Education. 2013; Pg 34-5.
- Goran A. Torsion of the gravid uterus. Goran A. ed. In Acute abdomen during pregnancy. Springer International Publishing Switzerland; 2014. pg 533.
- Nicholson WK, Coulson CC, McCoy MC, Semelka RC. Pelvic magnetic resonance imaging in the evaluation of uterine torsion. Obstet Gynecol 1995;85(5Pt2):888-90.
- Wilson D, Mahalingham A, Ross S. Third trimester uterine torsion: case report. J.Obstet Gynecol Can. 2006; 28(6):531-5.
Prabhu S, Mishra N, Savani G, Tintoiya I. Pendulous Abdomen Causing Levorotation of Uterus And Transverse Lie. JPGO 2017. Volume 4 No.4. Available from: http://www.jpgo.org/2017/04/pendulous-abdomen-causing-levorotation.html